Re: [PSES] Tamper-proof Hardware
Per: 3 to engage secretly or improperly in something. Wouldn't improperly be the key word, as it may expose a hazard? Larry Merchell From: John Woodgate Sent: Tuesday, April 9, 2019 2:36:47 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Tamper-proof Hardware We are not so far apart. You say that the text should not have appeared in a numbered clause that might be assumed to be normative. I say that it would be better not to have a numbered clause because it might seem to be normative. I think that few would assume that the normal INTRODUCTION text in an IEC standard is normative. See 13.2 of Directives Part 2. Best wishes John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk<http://www.woodjohn.uk> Rayleigh, Essex UK On 2019-04-09 10:28, John Allen wrote: John W When something that ambiguous, and which that could be construed as being a requirement, is placed in a prominent position in a standard, regardless or not of whether the clause in question is numbered, then it is obvious that it will (as it has done) raise issues and questions as to the potential effects on many other parts of that standard . BTW: it has been widely and authoritatively stated that 62368 is not a “Risk Assessment” standard, and appropriate rationales and requirements are thus given therein – but to then include an undefined term which might then be construed as a “requirement” is an open invitation for someone to decide that “he” has to risk assess how “tamper-proof” a particular design safety feature actually might be. Those are some of the reasons why I consider that the term in question should never have been included in the first place. John E Allen W. London, UK From: John Woodgate [mailto:j...@woodjohn.uk] Sent: 09 April 2019 09:40 To: John Allen; EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Tamper-proof Hardware I think that the major point is that Clause 0 is purely advisory. It seems reasonable in an advisory text to mention means to deter operations that might compromise safety, without going into exhaustive detail. It would seem harmless, so not worthy of suppression. I wouldn't have given the INTRODUCTION a clause number, because it creates an impression that it is normative. But then there are 10^6 things in 62368-1 that I would have done differently. Best wishes John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk<http://www.woodjohn.uk> Rayleigh, Essex UK On 2019-04-09 09:11, John Allen wrote: Rich Thanks for laying out the main definitions of “tamperproof”, and for your view on why my “story” is not an example thereof (it was only the one that I had “to-hand” at the time, and there must be many others :)) . Maybe, therefore, similar definitions/explanations should have been included in IEC 62368, so as to make it (much!) clearer to designers and testing/certification personnel as to the intent of the requirement because (obviously) there can be a considerable spread of interpretations of the requirement - or else John Cochran (and probably many others!) would not ask the question. As it stands, that “requirement” must thus be considered to be “ambiguous” at best, and therefore shouldn’t have been included in a standard in that form (I’m sure there must be a word to describe a definition with four different possible interpretations, but I’m afraid I don’t know it and thus “ambiguous” is the best that I can offer ATM!). In fact, given the definitions you quote, I would suggest that the term should NOT have been included in the standard at all because they imply the likelihood of various levels of intentional interference/criminality on the parts of possible perpetrators. However, it should not have been the intent of the 62368 standards-writing teams to address such issues - maybe YES if it were in a theft/ building-intrusion/ forgery prevention (etc.) standard, but NO in a broadly-targeted product safety standard. John E Allen W. London, UK From: Richard Nute [mailto:ri...@ieee.org] Sent: 08 April 2019 23:40 To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Tamper-proof Hardware >From dictionary.com: tamperproof adjective 1 that cannot be tampered with; impervious to tampering tamper verb (used without object) 1 to meddle, especially for the purpose of altering, damaging, or misusing (usually followed by with ) 2 to make changes in something, especially in order to falsify (usually followed by with ) 3 to engage secretly or improperly in something. 4 to engage in underhand or corrupt dealings, especially in order to influence improperly (usually followed by with ) The example provided by John Allen (UK) is not tampering as he did not take the unit apart for any of the above reasons. Using the above definiti
RE: Do not dial 9, 0, #, then hang up when requested.
I just verified this warning as valid with my local phone service (COX Cable). Larry Merchell Design Engineer Taiyo Yuden (USA) Inc. 1770 La Costa Meadows Drive San Marcos, Ca 92069 Tel: 760-510-3200 Fax: 760-471-4022 E-Mail: lmerch...@t-yuden.com Web: www.T-Yuden.com -Original Message- From: Lou Aiken [mailto:ai...@gulftel.com] Sent: Monday, March 19, 2001 10:26 AM To: david_l_tarnow...@email.whirlpool.com; emc-p...@ieee.org Subject: Re: Do not dial 9, 0, #, then hang up when requested. This does NOT happen when I try it between my two separate phone lines. Rgds. Lou Lou Aiken 27109 Palmetto Drive Orange Beach, AL 36561 U.S.A. tel1-334-981-6786 fax 1-334-981-3054 mobile 1-334-979-4648 - Original Message - From: david_l_tarnow...@email.whirlpool.com To: emc-p...@ieee.org Sent: Monday, March 19, 2001 11:06 AM Subject: Do not dial 9, 0, #, then hang up when requested. __ Forward Header __ Subject: Do not dial 9, 0, #, then hang up when requested. Author: cfil...@sears.com at INTERNET Date:3/19/2001 7:44 AM PLEASE READ THE FOLLOWING WARNING FROM IRV LEVINSON: I received a telephone call last evening from an individual identifying himself as an 'ATT Service Technician' who was conducting a test on telephone lines. He stated that to complete the test I should touch nine(9), zero (0), pound (#), and then hang up. Luckily, I was suspicious and refused. Upon contacting the telephone company, I was informed that by pushing 90#, you give the requesting individual full access to your telephone line, which enables them to place long distance calls billed to your home phone number. I was further informed that this scam has been originating from many local jails/prisons. I have also verified this information with UCB Telecom, Pacific Bell, MCI, Bell Atlantic and GTE. Please beware. DO NOT press 9 0 # for ANYONE. The GTE Security Department requested that I share this information with EVERYONE I KNOW. PLEASE pass this on to everyone YOU know. If you have mailing lists and/or newsletters from organizations you are connected with, I encourage you to pass on this information to them, too. After checking with Verizon, they said it was true so do not dial nine (9), zero (0), pound (#) and hang up for anyone! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: FW: [Fwd: [SI-LIST] : Copper balance] {Venting of PCBs}
Cortland, The holes or slots may also be required to meet the Maximum unpierced conductor area requirement of UL796 Standard for Printed-Wiring Boards for your particular PWB supplier. In the UL Recognized Component Directory (vol. 3, ZPMV2) it is listed as Maximum, Area, Diameter, Inches. Regards, Larry Merchell Taiyo Yuden (USA), Inc. San Marcos, CA -Original Message- From: Cortland Richmond [mailto:72146@compuserve.com] Sent: Wednesday, January 24, 2001 8:38 AM To: Debbie Mallory; ieee pstc list Subject: Re: FW: [Fwd: [SI-LIST] : Copper balance] Debbie, Doug Powell explained it as venting, where slots or holes are added to a plane in order to let vapor out. However, it is my belief that this is also done to keep copper balanced during the etching process. I may well be mistaken, but the EMI and signal integrity concerns we have with the practice are all valid. Cheers, Cortland == Original Message Follows Date: 23-Jan-01 07:25:06 MsgID: 1077-23952 ToID: 72146,373 From: Debbie Mallory INTERNET:debbie.mall...@fibre.com Subj: FW: [Fwd: [SI-LIST] : Copper balance] Chrg: $0.00 Imp: Norm Sens: StdReceipt: NoParts: 1 From: Debbie Mallory debbie.mall...@fibre.com Subject: FW: [Fwd: [SI-LIST] : Copper balance] List-Post: emc-pstc@listserv.ieee.org Date: Tue, 23 Jan 2001 07:21:35 -0800 Cortland, I, too, am having problems passing radiated emissions because of 350Mz originating from a 50MHz processor that uses a 50MHz oscillator. I thought I understood thieving until you said you have to put it on the ground plane also. Can you explain further why and how thieving is applied to the ground plane? Thanks. Regards, Debbie Mallory Advanced Fibre Communications Largo, FL == End of Original Message = --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
FCC Website Information
1. For Everyones Information, CFR's can be downloaded from (via Netscape): Federal Communication Commission Office of Engineering and Technology FCC Rules and Regulations located at: http://www.fcc.gov/oet/info/rules/ 2. I am looking for information regarding 47 CFR 68.304 Leakage current limitations. The standard states that the leakage current must be less that 10mA at 1500VAC from AC line to case [ (b) to (c) ], which looks like a Hipot test not a leakage test. Does anyone have any additional information regarding this? Thank you for any help. Larry Merchell Product Safety Engineer Xentek Power Systems lar...@electriciti.com
